Kidnapped by a assassin Killua X reader X Feitan

This book kind sucks oops This was started like 3 years ago so sorry that it sucks :) Y/n is a normal girl, well other than the fact that she is a foster kid and has had 2 different families this is her 3 fam but when a killer comes in and kills her dad and kidnapps her andr her best friend what will happen? FEITAN C...